﻿
#include <stdio.h>
int factorial(int n);
;int main (void)
{
     int n;

     scanf_s("%d", &n);
    printf("%d\n", factorial(n));
    
    return 0;
}
int factorial(int n)
{
    int i, fact = 1;

    for (i = 1; i <= n; i++)
        fact = fact * i;

    return fact;
}

        